Picornavirus is a positive single-stranded RNA virus with 7.2 Kb to 8.5 Kb, in which an RNA genome is only 7500 nt long. In addition, the virus is a very small globular non-enveloped virus with a size of approximately 22 nm to 30 nm, and is the oldest known virus. Rhinovirus, enterovirus, cardiovirus, aphthovirus, hepatovirus, etc. belong to picornavirus. 
At least 50% of cold-inducing pathogenic viruses are rhinovirus. However, therapeutic agents against rhinovirus infection have not yet been developed. As drugs that inhibit rhinoviruses, tremacamra (Turner R B et al., 1999, JAMA 281:1797-1804) which is a drug inhibiting rhinoviruses to be bound to ICAM-1, a receptor, in the form of sICAM-1, and a drug (Wang, Q M, 2001. Prog. drug Res. 229-253; Chen D H et al., 2003. Bioorg Med Chem Lett 13:3531-3536.; Dragovich P S et al., 2002. J Med Chem 45:1607-1623) which has a function to inhibit rhinovirus (HRV) 3C protease have been reported.
However, the tremacamra, a spray-type formulation, is disadvantageous in that it requires numerous administrations per day and that an effect thereof is low. Although an HRV 3C protease inhibitor was proved effective against HRV 14 in an in vitro experiment (Chen S H et al., 2003. Bioorg Med Chem Lett 13:3531-3536), a significant result was not obtained in an experiment using a monkey as an infectious model (Dragovich P S et al., 2002. J Med Chem 45:1607-1623).
Additionally, as formulations that react with a virus capsid, WIN 51711 (Otto M J et al., 1985, Antimicrob Agents Chemother 27(6):883-886), pirodavir (Brown R N et al., 2005. Bioorg Med Chem Lett 15(8): 2051-2055), and pleconaril (Pevear D C et al., 1999. Antimicrob Agents Chemother 43(9):2109-2115) have been reported. Further, enviroxime (Carraso L., 1994. 64:215-290) is being developed as a viral RNA synthesis inhibitor.
However, the pirodavir has a property that pharmacokinetic values are low even if it inhibits the proliferation of various rhinovirus serotypes. Further, the pirodavir also has a property to be easily hydrolyzed, and thus cannot be progressed to be used as a therapeutic agent. The pleconaril has a wide range of applications, such as rhinovirus, enterovirus, etc. (Hsiung G D & Wang J R 2000. J Microbiol Immunol Infect 33(1):1-8), but has not yet been approved by the US Food and Drug Administration (USFDA) due to drug interaction, marginal efficacy, and production of virus resistance.
Recently, RNAi has also been investigated as a therapeutic drug (Phipps et al., 2004. Antiviral Res. 61:49-55). However, it is disadvantageous in that target RNAi needs to be prepared separately depending on more than 100 types of rhinoviruses 
On the other hand, ribavirin is a compound in the form in which triazole carboxamide is bound to a ribose sugar. Further, the ribavirin has been reported to exhibit antiviral ability against FMD virus causing foot-and-mouth disease (Arias A et al., 2008, J Virol 82(4): 12346-12355), enterovirus causing hand-foot-mouth disease (Fengqin L et al., 2010 J Ethnopharmacol 127(2):221-228), and rhinovirus (Choi H J et al., 2010 J med Food 13(2): 326-328), which belong to the family Picornaviridae. Furthermore, the ribavirin is a drug used as a therapeutic agent along with interferon for treating infectious diseases of hepatitis C virus, a hepatovirus (Jain M K & Zoellner C 2010 Expert Opin Pharmacother 11(4):673-683).
However, the ribavirin is known to exacerbate heart disease by inducing severe anemia and is disadvantageous in that it induces various side effects, such as fatigue, headache, etc. (MacNicholas R & Norris S 2010 Aliment Pharmacol Ther 31(9):929-937). In this regard, there is a growing necessity to develop antiviral agents exhibiting significant antiviral effects without any side effects.
Enterovirus infection may cause cold, myocarditis, meningitis, hand-foot-mouth disease, etc., or may cause a neurological disorder. It is known that there are no therapeutic agents against enterovirus, except for symptomatic treatment.